Heat 1 tbsp oil in a frying pan over a high heat, add the duck breast and saute for 4-5 mins, turning. Season with salt and pepper. Reduce the heat to medium-low and cook the duck for a further 15-20 mins, turning occasionally.,Peel the orange completely. Remove the sections using a sharp knife then squeeze the juice from the pith. Mix juice with the mayonnaise.,______,Add the orange segments to the frying pan with the duck and fry for 30 seconds to 1 min, turning. Remove the duck from the pan and thinly slice. Layer the cabbage, orange segments, duck and lettuce into burger buns and spread with orange mayonnaise. Serve.